Analysis and optimization of geometry of 3D printer part cooling fan duct

Abstract

Part cooling fans are used in FDM 3D printers to control the deposition quality and warping issues. However, the fan ducts used for the purpose are often non-optimized, and therefore, the performance of such ducts can be improved by analyzing the geometry and adopting necessary modifications. This work looks into the geometry of the part cooling fan duct of a common commercial 3D printer, and studies the influence of a convergent-divergent type duct opening on the flow behavior. The inlet and outlet angles and the throat length have been analyzed numerically to identify the most suitable geometry. Results indicate that there are optimum values for all of these three geometrical parameters to obtain the highest air flow velocity at the outlet, and the flow behavior deteriorates beyond such optimum parameters. From the numerical analysis, the optimized convergent-divergent duct having 20° outlet angle, 3 mm throat length, and 40° inlet angle can increase the average air flow velocity by approximately 23% over the air flow velocity of a standard part cooling fan without the convergent- divergent section.